HPMC vs HEMC: 6 Differences for Effective Cellulose Ethers Comparison

1. HPMC and HEMC: Difference in Functional Groups

HPMC: Methoxy (-OCH3), Hydroxypropoxy (-OCHCH2OH) groups.

HEMC: Methoxy (-OCH3), Hydroxyethyl (-OCH2CH2OH) groups.

> Methoxy Group (-OCH3)

Lacks a hydroxyl group, exhibits low polarity, and has poor hydrophilicity.

> Hydroxyethyl Group (-OCH2CH2OH)

Contains a hydroxyl group, demonstrates higher polarity, and excellent hydrophilicity.

> Hydroxypropyl Group (-OCHCH2OH)

It contains a hydroxyl group and has good hydrophilicity. However, due to steric hindrance from the methyl group, its polarity is less than that of hydroxyethyl. This issue may lead to HPMC having a less effective thickening effect than HEMC.

2. HPMC and HEMC: Differences in Degree of Substitution (DS) Standards

The degree of substitution of hydroxyethyl and hydroxypropyl groups is relatively close.

Molecular Weight of the Functional Groups

> Hydroxyethyl: 60

> Hydroxypropyl: 74

This implies that even with the same degree of substitution (DS) in terms of mass fraction, HEMC contains a higher number of hydroxyethyl groups compared to the other. So, HEMC has a higher DS than HPMC.

3. HPMC and HEMC: Differences in the Impact of Functional Group

A higher degree of hydrophilic substitution leads to stronger binding with water molecules. Methyl cellulose ethers can dissolve in cold water. But, as the solution temperature rises, there will be an issue comes up. The detachment from cellulose molecules and forming gel-like precipitates. This is also known as gelation.

Gel Temperature

HEMC’s gel temperature is higher than HPMC. WOTAIchem’s standard HEMC gel temperature is around 75° to 85°. And the HPMC gelation temperature is around 55° to 75°.

Therefore, if you reside in countries with hot climates like India, Indonesia, or Africa, MHEC powder is the best choice! You can also choose our pure HEMC powder for construction projects in extreme environments.

Its application performance shows that at the same dosage and viscosity level. HEMC has a higher water retention rate at high temperatures, as illustrated in the following graph:

4. HPMC and HEMC: Differences in Water Solubility

HPMC with delayed dissolution is called surface-treated HPMC. It readily dissolves in hot water and forms clusters in cold water before swelling. In contrast, HEMC readily dissolves in cold water but does not dissolve in hot water. So, HPMC solubility is better than HEMC’s.

5. HPMC and HEMC: Difference in Price

Typically, the HEMC powder price is slightly higher than that of MHEC powder price. The main distinction lies in what you prioritize.

If you have a sufficient budget, we recommend using MHEC. However, the choice between these cellulose ethers should also be based on your specific application needs.

6. HPMC and HEMC: Different in Applications

HEMC is ideal for environments with temperatures around 45-50°C. It is suitable for summer construction. When used in equivalent amounts to HPMC, HEMC demonstrates superior water retention, heat resistance, and sag resistance. HEMC also introduces finer air bubbles compared to HPMC.

Other benefits of HEMC powder:

> Extending setting time,

> Enhancing workability.

> Better pumpability during construction.